Coronavirus: Here's how it spread in Santa Clara County Skip to content

Health |
Coronavirus: Here’s how it spread in Santa Clara County

“The vast majority of cases are randomly scattered.” — Dr. Sara Cody, Santa Clara County health officer

  • SAN JOSE, CALIFORNIA - MARCH 11: A Transportation Security Administration...

    SAN JOSE, CALIFORNIA - MARCH 11: A Transportation Security Administration officer screens passengers at Mineta San Jose International Airport, Wednesday, March 11, 2020, in San Jose, Calif. The TSA announced yesterday that three of their officers had tested positive for coronavirus. (Karl Mondon/Bay Area News Group)

  • SAN JOSE - MARCH 22: A person jogs near the...

    SAN JOSE - MARCH 22: A person jogs near the palm trees near SAP Center on West Santa Clara Street during a quiet day in downtown San Jose, Calif., on Sunday, March 22, 2020.(Randy Vazquez / Bay Area News Group)

  • SANTA CLARA - MARCH 22: A person runs passed the...

    SANTA CLARA - MARCH 22: A person runs passed the Santa Clara Convention Center in Santa Clara, Calif., on Sunday, March 22, 2020.(Randy Vazquez / Bay Area News Group)

  • SAN JOSE - MARCH 22: A cyclist rides down West...

    SAN JOSE - MARCH 22: A cyclist rides down West Santa Clara Street during a quiet day in downtown San Jose, Calif., on Sunday, March 22, 2020.(Randy Vazquez / Bay Area News Group)

  • SANTA CLARA - MARCH 22: The Santa Clara Convention Center...

    SANTA CLARA - MARCH 22: The Santa Clara Convention Center in Santa Clara, Calif., on Sunday, March 22, 2020.(Randy Vazquez / Bay Area News Group)

  • SAN JOSE - MARCH 22: Pedestrians cross West Santa Clara...

    SAN JOSE - MARCH 22: Pedestrians cross West Santa Clara Street during a quiet day in downtown San Jose, Calif., on Sunday, March 22, 2020.(Randy Vazquez / Bay Area News Group)

  • SAN JOSE, CA - MARCH 20: Naksh Nautiyal, 3, of...

    SAN JOSE, CA - MARCH 20: Naksh Nautiyal, 3, of Santa Clara, watches planes take off and land at Norman Y. Mineta San Jose International Airport from the safety of the family car in San Jose, Calif., on Friday, March 20, 2020. Nautiyal's parents brought him to the airport after spending the day inside at home. In a news conference Thursday evening, California Governor Gavin Newsom ordered all of the state's 40 million residents to stay at home, with exceptions for essential work, food or other needs. Outdoor recreation and exercise is allowed as long as social distancing and other “common sense” preventive measures are followed. (Anda Chu/Bay Area News Group)

  • SANTA CLARA - MARCH 19: People distance themselves from each...

    SANTA CLARA - MARCH 19: People distance themselves from each other during a press conference held by local officials and members of the San Francisco 49ers organization outside of Levi's Stadium in Santa Clara, Calif., on Thursday, March 19, 2020. The 49ers announced they will contribute $500,000 to support employees and the community in response to the COVID-19 public health emergency. (Randy Vazquez / Bay Area News Group)

  • SANTA CLARA - MARCH 19: San Francisco 49ers president Al...

    (Randy Vazquez / Bay Area News Group)

    SANTA CLARA - MARCH 19: San Francisco 49ers president Al Guido, left, speaks at a press conference held by local officials and members of the 49ers organization outside of Levi's Stadium in Santa Clara, Calif., on Thursday, March 19, 2020. The 49ers announced they will contribute $500,000 to support employees and the community in response to the COVID-19 public health emergency. (Randy Vazquez / Bay Area News Group)

  • SAN JOSE, CALIFORNIA - MARCH 11: A Transportation Security Administration...

    SAN JOSE, CALIFORNIA - MARCH 11: A Transportation Security Administration officer screens passengers at Mineta San Jose International Airport, Wednesday, March 11, 2020, in San Jose, Calif. The TSA announced yesterday that three of their officers had tested positive for coronavirus. (Karl Mondon/Bay Area News Group)

  • SANTA CLARA - MARCH 19: San Jose mayor Sam Liccardo,...

    SANTA CLARA - MARCH 19: San Jose mayor Sam Liccardo, right, greets Silicon Valley Foundation president and CEO Nicole Taylor, left, before a press conference held by local officials and members of the San Francisco 49ers organization outside of Levi's Stadium in Santa Clara, Calif., on Thursday, March 19, 2020. The 49ers announced they will contribute $500,000 to support employees and the community in response to the COVID-19 public health emergency. (Randy Vazquez / Bay Area News Group)

  • LOS GATOS - MARCH 17: Alea Bowen, center, and her...

    LOS GATOS - MARCH 17: Alea Bowen, center, and her mother Michelle, right, walk with their dog Buddy, left, in downtown Los Gatos, Calif., on Tuesday, March 17, 2020. It was a quieter scene at usually busy downtown area due to shelter in place orders that were announced yesterday in Santa Clara County. (Randy Vazquez / Bay Area News Group)

of

Expand
Lisa Krieger, science and research reporter, San Jose Mercury News, for her Wordpress profile. (Michael Malone/Bay Area News Group)
PUBLISHED: | UPDATED:

CLICK HERE if you’re having a problem viewing the photos on a mobile device.

With a diverse and well-traveled population, Santa Clara County is especially vulnerable to contagion.

Yet the arrival of a new virus early this year went completely undetected, giving it time to widely seed our region before we even knew it was here, the county’s top public health official says. By early March, that virus was so widespread that three TSA agents at San Jose International Airport contracted it not from each other but from entirely separate sources.

In an exclusive interview, county health officer Dr. Sara Cody revealed the depth of the coronavirus containment challenge facing the county, Northern California’s hardest-hit location — and why infections exploded so quickly, demanding an aggressive “shelter-in-place” order.

“The vast majority of cases are randomly scattered” in Santa Clara County, not clustered in the small and easily identifiable groups seen in some other locations, she said in a Friday interview, one of the few she has given since the crisis began.

Ideally, officials would deploy disease detectives to each of the 302 patients in the county, asking questions that could help disrupt the social network of coronavirus: Did they play bridge last week? Did they join a book club? Which aisles did they shop at Home Depot, Walgreens and Safeway? And who are their friends and family?

“We don’t have a workforce to do that,” said Cody. “And that’s a real problem. Because we need to be able to interrupt every chain of transmission that we possibly can.”

The very nature of Santa Clara County puts it at risk, she said.  We’re diverse, with residents from all over the globe. And we’re travelers, with easy access to three international airports.

Other Bay Area counties share those same characteristics, helping to explain why our region’s total case count soared to 694 on Sunday. While the number of cases in adjoining counties fall short of Santa Clara County’s total of 302, they are still high, with 117 in San Mateo, 108 in San Francisco, 106 in Alameda and 61 in Contra Costa County.

If this illness was a wildfire, there would be no single giant inferno. Instead, it’s many far-flung hotspots.

Most cases are mild and don’t require hospitalization. Given the shortage of available tests, they may not even be detected. Yet people with minor illness can unwittingly transmit the virus to others, with catastrophic consequences for an estimated five percent of those affected.

As early as January, local physicians called the county Department of Health to report illnesses that didn’t meet the formal U.S. Centers for Disease Control definition for coronavirus symptoms — but were suspect.

“We were not able to test them. There just wasn’t the capacity to do that,” because the patients weren’t eligible under the CDC’s strict testing criteria, Cody said.

“We absolutely missed people. No question,” she said. “All the people that were ‘return travelers’ with very mild symptoms — we weren’t testing them,” she said. We couldn’t test their friends or family members, either, she added.

“It was like looking through a slit lamp,” she said, referring to a narrowly-focused microscope commonly used in eye exams. “You just can’t see as broadly as you need to.”

It wasn’t until late February that the county finally got federal approval to start running tests in its own laboratory.

Immediately, she sensed that the problem might be far larger than imagined.

The very first test conducted by the county came back positive — and the patient, a woman in her 60s, had no history of international travel or contact with a traveler or infected person. How and where was she exposed? No one knew. That told Cody that the virus was lurking in the general population.

“It was a real signal, a game changer,” said Cody. “That indicated that somehow she was exposed to the virus somewhere in our county, although we didn’t know where. … That was our first signal that we had transmission in our community.”

Cody was further alarmed when three Transportation Security Officers at Mineta San Jose International Airport also tested positive.

These workers had no links to each other — showing that they didn’t catch the illness from each other but from independent exposure in a community where the virus was already running rampant.

“TSA workers work in a place where they’re in contact with incredible numbers of the traveling public. … I can’t think of another type of worker who is exposed to so many people in a day,” she said. “So they’re sentinels.”

“What that cluster represented,” she recalled, “was: ‘Wow, we have a significant amount of community transmission.’ ”

Confronted with early outbreaks like this, countries such as Singapore and Taiwan launched aggressive “contact tracing” programs that discover the details of where patients live, play and work. Close contacts of patients are quarantined to limit viral spread.

The Chinese city of Wuhan, the epicenter of the outbreak, brought in 1,500 epidemiologists to conduct “contact tracing,” assigning five experts to every single case, according to Dr. Michele Barry, Senior Associate Dean for Global Health at Stanford University’s School of Medicine.

“We can’t use that same strategy” due to short staffing, said Cody. “Trying to map and figure out where are some hotspots for transmission — we really don’t have the data to enable us to do that. That’s still a pretty fuzzy part of the picture.”

Instead, the country is focusing its efforts on detecting outbreaks when they occur in easily recognized groups — particularly among people who are at high risk, such as residents of long-term care facilities, she said.

“We want to know as fast as we can and both remove them from the group and test them to prevent a chain of transmission in a highly vulnerable group,” she said.

That’s also why the county deployed an early “shelter-in-place” order. Because experts can’t detect and encircle each and every case, the general community needs to protect itself through distancing, she said.

Early on, we were “well behind where we needed to be to understand the magnitude of transmission that was occurring in the community — undetected and unbeknownst to us,” she said. “But we are where we are.”

“What can we do now?” she asked. “That’s the focus.”